51 / 2019-09-01 12:42:18

NUMERICAL SIMULATION OF MULTI-COMPONENT STRATIFICATION FLOWS

convection flow,oceanography

In this study we conduct large scale direct numerical simulations for buoyancy-driven convection flow where fluid density depends on two scalar components. Such flows are omnipresent in ocean, known as double diffusion convection, and many other natural and engineering applications. They play critical roles in the vertical mixing and transport in the ocean. Specifically, we study double diffusion in the finger regime widely found in (sub-) tropic ocean, where the flow is driven by an unstable salinity gradient and stabilized by a temperature gradient. Scaling laws are proposed to describe the transport properties of finger structures. We also realize the striking thermohaline staircases, and reveal the different transport properties between finger layers within staircases and those single finger layers. All these findings greatly improve our understandings about the double diffusion in the ocean, and clearly demonstrate the advantages of numerical simulations.